BEIRUT - In a letter to the United Nations, the Lebanese Foreign Ministry said the weapons warehouse that exploded on July 14 belonged to the Israel Defense Forces (IDF).

The weapons were "left behind by the Israelis" after the Second Lebanon War (in the summer of 2006), the Lebanese Foreign Ministry claimed, according to the London-based Arabic daily al-Hayat.

On July 14, a massive explosion decimated an abandoned building in a Lebanese village near the border with Israel.

Last week, at an emergency meeting of the Security Council, UN Under-Secretary-General for Peacekeeping Operations Alain Le Roy told council members the weapons warehouse belonged to Hezbollah.

Le Roy said Hezbollah operatives in the area prevented UNIFIL troops (UN peacekeeping forces) from investigating the explosion.

"A number of indications suggest that the [weapons] depot belonged to Hezbollah and [it was] in contrast to previous discoveries by UNIFIL and the Lebanese Armed Forces of weapons and ammunition that was not abandoned, but rather actively maintained," Le Roy told the 15-member Security Council.

Meanwhile, the IDF has been monitoring stepped up activity by Hezbollah forces in southern Lebanon.

The July 14 explosion was further evidence that the terror group has been building up its weapons stockpiles in violition of UN Resolution 1701, which marked the end of the war.

Senior IDF officials believe Iran and Syria have helped replenish Hezbollah's missile cache, while its operatives have rebuilt the group's network of bunkers south of the Litani River.